Arc lamp



w. F. WITTE June 22 1954 ARC LAMP 3 Sheets-Sheet 1 Filed Sept. 28, 1950 FIG-l WERNERT F. WITTE INVENTOR ATTORNEY W. F. WITTE ARC LAMP 3 Sheets-Sheet 2 Filed Sept. 28, 1950 FlGZ WERNERT F. WITTE INVENTOR ATTORNEY June 22, 1954 w W|TTE 2,681,983

ARC LAMP Filed Sept. 28, 1950 5 Sheets-Sheet 3 WERNERT F. WITTE INVENTOR ATTORNEY Patented June 22, 1954 UNITED STATES PATENT OFFICE 6 Claims. 1

My invention relates toare lamps, and the principal object of my invention is to provide suitable means for stabilizing the arc, improving combustion, directing the flame, and avoiding undue increase in temperature during operation of the lamp.

In the drawings accompanying this specification and forming a part of this application I have shown for purposes of illustration what I now consider to be the best mode of carrying my invention into practice, and in these drawmgs:

Figure 1 is a side view of an arc lamp embodying the selected form of my invention, but omitting the near side door of the lamp to afford a View of part of the interior of the lamp;

Figure 2 is a plan View of a portion of the interior of the lamp of Figure 1;

Figure 3 is an enlarged transverse section through the positive head, on the line 3-3 of Figure 1;

. Figure 4 is a partial elevation of the forward end of the positive head, to the same scale as Figure 3; and

Figure 5 is a correspondingly enlarged side elevation of the negative head.

The lamp l herein shown and described comprises a housing H containing a platform [2 on which are mounted a positive head 20 and a negative head 50 carrying respectively a positive electrode 2| and a negative electrode between which isformed the desired arcresulting in the emission of light particularly from the crater 22 at the forward end of the positive electrode 2| and to a reflector I3 and thence to one or more lenses, not shown, located in a cone l4 extending from the forward end of the housing H.

According to the present disclosure the positive head comprises a hollow casting 23, providedat its lower end with a flange 24 by which it is mounted to the platform I2 by suitable securing means 25, and carrying at its upper end three rollers 26 and 2611, serving to supportthe positive electrode 2|, rotated to rotate the electrode 2| to avoid uneven burning and skewed to simultaneously eiTect' longitudinal movement of the electrode 21 to maintain the crater 22 in proper position relative to the reflector [3.

In the present embodiment the describd rotation of the rollers 26 is accomplished by a drive comprising a head shaft 2! carrying a gear 28 meshing with gears 29 carried by the opposite ends of shafts 30 on which the rollers 26 are mounted, a vertical shaft 3| operating the head shaft 2'! by means of coacting bevel gears 32 and 33, and a transverse shaft 34 operating the vertical shaft 3| by means of similar coacting bevel gears, not shown, and normally driven by a positive electrode drive motor 35 through a suitable speed reduction mechanism 36 and a friction clutch 3? provided to permit manual operation of the transverse shaft 34 by means of a hand crank 38, particularly for preliminary adjustment of the longitudinal position of the electrode 2! and. crater 22.

Further, as shown particularly in Figure 3, the one roller shaft 52% is mounted in an arm 38 pivoted to the head fill at $9, biased by a spring ii) to press the corresponding roller 26a against the electrode 2! to cause the electrode iii to be held and driven as described, but retractible by means of a cam 4| operable by a suitable lever 42, to thus retract the roller 26a particularly to permit insertion or removal of an electrode 2 l.

According to the present disclosure the negative head 58 comprises a bracket 52 mounted to the platform I2 by suitable securing means 53, and as shown particularly in Figure 5, carrying a guideway 54 in which is reciprocably supported a negative electrode carrier 55 mounting the negative electrode 5| and reciprocable longitudinally of the guideway 54 by means of a screw 56 supported from the bracket 52 and received in a cooperatingly screw-threaded aperture in the body of the carrier 55.

In the instant embodiment the screw 56 is rotated by means of an intermediate worm gear 57 engaging a driven worm gear 58 unitary with the screw 56 and operated by a driving worm gear, not shown, mounted on a second transverse shaft 59 normally driven by a negative electrode motor 60 through a suitable speed reduction mechanism Bi and afriction clutch 62 provided to permit manual operation of the transverse shaft 59 by means of a hand crank 63, particularly for preliminary adjustment of the longitudinal position of the carrier 55 and negative electrode 5!.

In addition to the foregoing the instant lamp l0 comprises means for directing a current of air against the flame of the arc, comprising an air tube or nozzle ill mounted on the negative electrode bracket 52 and supplied from an air reservoir H formed by the lamp housing H and the platform 92 and itself supplied by two blowers l2 and '13 combined with and operate-d by the electrode feed motors 35 and 60.

As appears from thedrawings, the air tube 10 directs the air substantially parallel to the direction of the extent of the negative electrode El, against the arc, whereby the flame is caused to extend substantially vertically, and further is somewhat flattened and greatly shortened, operating to avoid wandering of the flame sideways of the positive electrode, or from one side of the positive electrode to the other, thus to stabilize the arc.

Further the air current from the tube l opcrates to blow away from the reflector It the products of combustion which otherwise deposit on and spoil the surface of the reflector and by reason of local difierence in thermal expansion are likely to cause cracking or crazing of the reflector surface.

In addition, at the time of starting the arc the air current also provides suflicient air for sub-- stantially complete combustion of all material dislodged from the electrodes, and thus operates efiectively to prevent the black. soot particles that otherwise would be emitted. and deposited. either on the reflector or on the interior of the housing.

Furthermore, in the present lamp air from the reservoir ll also passes through a passage ii in the negative electrode bracket 52, resulting in reducing the temperature or the negative head, and through the cavity '18 of the positive head 2%, resulting in cooling the positive head, and particularly the table i4, lower contact block it,

spring pressed upper contact block is, by which the current is conducted to the positive electrode 2|, and to facilitate maintenance of the contact blocks '15 and '16 at a minimum temperature, in

the present embodiment they are faced with sila ver, resulting in lower electrical resistance, and thereby in decreased generation of heat to be removed.

Thus the described embodiment adequately accomplishes at least the principal object of my invention, and on the other hand, obviously various changes and modifications may be made, and therefore my invention is not to be regarded as limited to the particular embodiment herein shown and described, and I claim as my invention:

1. An arc lamp comprising cooperating eiectrodes, constructed and arranged for the production of an arc therebetween, a first electric motor,

connections whereby said first motor is operative to feed one of said electrodes, a second electric motor, connections whereby said second motor is operative to feed the other of said electrodes, an air reservoir provided by said lamp, a first blower operated by said first motor and connected to flow air into said reservoir, a second blower operated by said second motor also connected to flow air into said reservoir, and means constructed and arranged to flow a stream of air from said reservoir substantially parallel with one of said electrodes and against the flame of the arc.

2. An arc lamp comprising cooperating positive and negative electrodes constructed and arranged for the production of an arc therebetween, an air reservoir provided by said lamp, means operative to feed air to said reservoir, and a nozzle associated with and parallel to said negative electrode, said nozzle located outside the angle formed by said electrodes and connected to said reservoir so as to flow a stream of air from said reservoir substantially parallel with the neg ative electrode and against the flame of the are.

3. An arc lamp comprising cooperating positive and negative electrodes constructed and arranged for the production of an arc therebetween, a re fiector arranged to receive and reflect light from said arc, and a nozzle associated with and parallel to said negative electrode, said nozzle located outside the angle formed by said electrodes and connected to said reservoir so as to flow a stream of air from said reservoir substantially parallel with the negative electrode and against the flame of arc and away from said reflector.

i An arc lamp comprising cooperating positive and negative electrodes constructed and arranged for the production of an are therebetween, an electric motor, connections whereby said motor is operative to feed at least one of said electrodes, a blower operated by said motor,

and a nozzle associated with and parallel to said negative electrode, said nozzle located outside the angle formed by said electrodes and connected to said blower so as to direct a stream of air from the blower substantially parallel with the negative electrode against the flame of the arc to control the relative position of the flame.

5. An arc lamp comprising cooperating positive and negative electrodes constructed and arranged for production of an arc therebetween, supports for said electrodes, the positive electrode being positioned substantially horizontally and the negative electrode angularly disposed with respect to the positive electrode, an air reservoir provided by said lamp, means to supply air to said reservoir to establish air pressure in said reservoir, and a nozzle associated with and parallel to said negative electrode, said nozzle located outside the angle formed by said electrodes and connected to said reservoir to flow an air stream from said reservoir paralled with the negative electrode and against the flame of the arc to direct the flame of the arc in a substantially vertical path, the support for the positive electrode being of hollow configuration through which. air from the said reservoir is conveyed to cool the support.

6. An arc lamp including cooperating positive and negative electrodes constructed and arranged for the production of an arc therebetween, an optical member arranged to receive and transmit light from said are, said positive electrode being disposed on the axis of the optical member, said negative electrode being arranged at an angle less than with respect to the positive electrode, a nozzle associated with and parallel to said negative electrode, and means to supply air to said nozzle, said nozzle located outside said angle formed by said electrodes so as to direct air stream substantially parallel with the negative electrode and against the flame of the arc to cause the flame to move in a direction substantially normal to the axis of the optical member to avoid deposit of products of combustion upon the optical member.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,133,508 Schoop Mar. 30, 1915 1,318,701 Sperry Oct. 14, 1919 13791530 Sperry -1 Jan. 1, 1924 1,714,242 Riccio May 21, 1929 1,757,526 House June 24, 1930 2,160,490 Strong May 30, 1939 2,510,102 Gretener June 6, 1950 FOREIGN PATENTS Number Country Date 169,496 Germany July 20, 1904 789,761 France Aug. 26, 1935- 

